Intergeneric hybrids of Triticum aestivum × Leymus multicaulis

Hybrids were obtained at a frequency of 0.53% of the pollinated florets by pollination of Triticum aestivum (2n = 6x = 42, AABBDD) cv. Norin 29 with Leymus multicaulis (2n = 4x = 28, JJNN). The hybrid plants were taller than both parents and the floral structure of the hybrid spike resembled a modified wheat spike. The hybrids had the expected somatic chromosome number of 35 (ABDJN). The average bivalent frequency per cell at metaphase I in the meiocytes was very low, 0.59 and 0.45, respectively, for the two hybrids studied, suggesting the absence of homology between the parental genomes. The meiotic abnormalities observed consisted of lagging chromosomes and cytokinesis irregularities, leading to the production of polyads containing micronuclei at the quartet stage. The backcrossing of one hybrid to wheat cv. Fukuho resulted in the production of one plant with 56 chromosomes. Preliminary results on the evaluation of the BC3 and BC2F2 derivatives for barley yellow dwarf virus resistance (BYDV) suggested that the transfer of BYDV resistance genes from L. multicaulis to wheat is possible.Key words: intergeneric hybrids, Leymus, wheat, rye-grass, wild rye, embryo rescue.